Vehicles, and particularly trucks, are conventionally provided with externally mounted rear view mirrors of elongated, rectangular shape in order to afford maximum visibility of objects to the side and rear of the vehicle. Since these mirrors are exposed to the elements, precipitation collects on the mirror surface, thereby reducing the driver's visibility and establishing the need for a mirror wiper.
Conventional wipers, such as used for windshields, are unsatisfactory for this purpose, since they move in an arc and therefore can only clean a portion of an elongated, rectangular mirror. In recent years, power operated wiper blade assemblies have been developed wherein the wiper blade operates in a reciprocating linear motion across the mirror surface, cleaning off substantially all of the mirror surface. Assemblies of this type are illustrated in U.S. Pat. Nos. 3,526,920, 3,618,156, 3,968,537 and 4,037,286.
One problem which has occurred in the use of these assemblies is that a number of mechanical parts are necessary to carry out the linear wiping operation, the arrangement of which parts is such that the assemblies are bulky and cumbersome, and the appearance thereof has affected the adoption thereof as standard equipment for vehicles.